The invention relates to an automatically controlled washing machine with a detergent dispensing facility disposed in the upper machine space, said facility having at least one chamber for a hand-dosed addition of a portion of powder or liquid detergent and a supply channel for supplying fresh water for each chamber, with at least one storage container disposed in the machine space for liquid or gel-type detergent aid, to which a facility for the automatic dosing of the stored detergent aid is assigned, comprising a transfer line for supplying the dose to the washing machine tub.
Such a washing machine is known from DE 34 03 622 A1. In it is disposed a storage container for liquid detergent aids in the detergent dispensing facility behind the widely known chambers for supplying a manually dosed quantity of detergent aid. The transfer line from the dosing facility opens directly into the same channel to the tub as the fresh water supply, to which manually dosed detergent aids have been added. However for correct operation of the dosing facility the detergent drawer accommodating it and the chambers has to move out of the cavity of the housing of the detergent dispensing facility and back into it. This causes the automatically dosed quantity of detergent aid to be retained in an intermediate container, until it is subjected to the action of fresh water through its own fresh water channel and fed to the transfer line by way of a suction lifter.
Independently of this dosable detergent aid it is possible to supply manually dosed detergent to the laundry treatment process in the known manner from the detergent dispensing facility housed in the upper machine space. The known washing machine is thus structured in a complex manner with a plurality of additional facilities, leaving little space for the storage container. Only relatively small quantities can therefore be stored.
If however the automatically dosed quantity of detergent aid is to be supplied to the tub immediately without intermediate preparation, then a fresh water storage container kept separately at a sufficiently high level can be provided according to DE 39 33 007 A1 to flush out the transfer line, otherwise the transfer line would become encrusted or would gradually become blocked due to the coagulation of detergent residues. With the known apparatus the discharge lines of the storage facility, which are provided with a dosing facility, open into a premix chamber, from whence the mixture of fresh water and detergent dose is transported to the tub.
In a further known washing machine (DE 40 14 359 A1) the transfer line is integrated within a pressure sensor tube of a water level sensor. Since the pressure sensor tube has to open out very low down in the tub anyway, so that the water level can be detected reliably, the outlet opening of the transfer line is automatically always below the washing liquor level, so that the constantly wet opening is consistently flushed out. Deposits of encrusting or coagulating detergent aid are therefore impossible. However separate lines have to be positioned within the washing machine for this purpose, so that the automatically dosed quantity of detergent aid reaches the tub. If the washing machine is not used for a fairly long period, residues of the dosed detergent aid can however be deposited in the long line and solidify there.
Such stores of detergents or there components and their automatic metering and supply facilitate the customer's work considerably in respect of the replenishment of detergent aids. However all known washing machines have the shared disadvantage that dosed detergent residues can be deposited anywhere on the path to the tub and when solidified can cause operational failure. Frequent cleaning of such parts is unavoidable but difficult. This problem is resolved with one of the known washing machines (DE 39 33 007 A1) but so many additional measures are implemented for this purpose that the resulting additional outlay makes the machine unacceptably more expensive.